Honey-bee–associated prokaryotic viral communities reveal wide viral diversity and a profound metabolic coding potential

Significance

This study uses viral-like particle purification and subsequent unbiased genome sequencing to identify prokaryotic viruses associated with Apis mellifera. Interestingly, bacteriophages found in honey bees show a high diversity and span different viral taxa. This diversity sharply contrasts with the state-of-the-art knowledge on the relatively simple bee bacterial microbiome. The identification of multiple auxiliary metabolic genes suggests that these bacteriophages possess the coding potential to intervene in essential microbial pathways related to health and possibly also to disease. This study sheds light on a neglected part of the bee microbiota and opens avenues of in vivo research on the interaction of bacteriophages with their bacterial host, which likely has strongly underappreciated consequences on bee health.

Abstract

Honey bees ( Apis mellifera) produce an enormous economic value through their pollination activities and play a central role in the biodiversity of entire ecosystems. Recent efforts have revealed the substantial influence that the gut microbiota exert on bee development, food digestion, and homeostasis in general. In this study, deep sequencing was used to characterize prokaryotic viral communities associated with honey bees, which was a blind spot in research up until now. The vast majority of the prokaryotic viral populations are novel at the genus level, and most of the encoded proteins comprise unknown functions. Nevertheless, genomes of bacteriophages were predicted to infect nearly every major bee-gut bacterium, and functional annotation and auxiliary metabolic gene discovery imply the potential to influence microbial metabolism. Furthermore, undiscovered genes involved in the synthesis of secondary metabolic biosynthetic gene clusters reflect a wealth of previously untapped enzymatic resources hidden in the bee bacteriophage community.